GNU PG

Overview

Hints and tips for using GPG encryption and signing tool from the GnuPG system.

Create a new Public and Private key pair

  • gpg --gen-key

Specify a different directory for creating the keyrings

  • gpg --homedir /home/xxx --gen-key

Creating a detached ascii signature

  • gpg --sign --detach-sign --armor file_to_be_signed

or

  • gpg -s -b -a file_to_be_signed

Signature Compatible with PGP

See http://www.gnupg.org/documentation/faqs.en.html#q5.1

  • gpg --sign --detach-sign --armor --compress-algo 1 --cipher-algo cast5 file_to_be_signed

    or

  • gpg --sign --detach-sign --armor --compress-algo 1 --cipher-algo 3des file_to_be_signed

Verifying a detached signature

  • gpg --verify signature_file signed_file

Exporting keys

These options allow you to transfer public and private keys to another machine. You can also export your trust database. You may also want to transfer your .gnupg/options or .gnupg/gpg.conf files too.

Export all public keys

  • gpg --export --armor > my_public_keys

Export specific public key

  • gpg --export --armor my.name@domain.tld > my_public_key

Export all private keys

  • gpg --export-secret-keys --armor > my_secret_keys

Export trust ownership

  • gpg --export-ownertrust --armor > my_owner_trust

Importing keys

Importing public keys

  • gpg --import my_public_keys

Importing private keys

  • gpg --import --allow-secret-key-import my_secret_keys

Importing owner trust relationships

  • gpg --import-ownertrust my_owner_trust

Import a key from a dowloaded KEY file

  • gpg --import KEY_FILE_NAME

Importing a key from a public server

Imports the specified key from the specified public key server and adds it to your key chain.

  • gpg --keyserver wwwkeys.pgp.net --recv-keys 0x5072E1F5

Display Fingerprint

  • gpg --fingerprint user.name

Signing a key

  • gpg --edit-key KEYNAME
  • sign
  • quit

Trusting a key

You need to sign the key first. See Signing a key

  • gpg --edit-key KEYNAME
  • trust
  • 4
  • quit

Updating the expiration date

  • gpg --edit-key YOUR_KEY
  • expire

Enter the period to extend the expiration date by, e.g. 1y

Then select the sub key and extend that too:

  • key 1
  • expire
  • 1y
  • quit

Specifying an alternate location for the keyrings

gpg --keyring=/somewhere/else/pubring.gpg
   --secret-keyring=/somewhere/else/secring.gpg encrypted.gpg

Linux GUI Front-Ends for GnuPG

Windows Usage

See http://www.glump.net/dokuwiki/gpg/gpg_intro

Resources

-- Frank Dean - 26 Sep 2004